The patients, who had been in contact with psychiatric services in the 12 months before they killed, fell through the net as they refused to take medication or failed to keep appointments for treatment. The inquiry blames a 'lack of co-ordination of support and failure by carers to interact' for the loss of contact.
The report, published today, will heighten controversy over the Government's care in the community policy under which more mentally ill people are being treated outside hospitals.
The inquiry was commissioned by the Department of Health in October 1991 after Carol Ann Barratt, a former psychiatric patient, stabbed to death a girl of 11 in a shopping centre two days after being released from hospital. She had been detained two weeks earlier after she tried to kill another girl in the precinct and was discharged by a consultant psychiatrist even though her release had been blocked three days earlier by a panel of medical experts.
The report contains the preliminary results of a confidential inquiry which traced 100 cases since 1991 in which the killer was subsequently admitted to a psychiatric hopsital. Of those, 34 had been in contact with psychiatric services in the previous 12 months and the inquiry team obtained details from their consultant in 22 cases.
One case studied was that of Christopher Clunis, a paranoid schizophrenic who killed Jonathan Zito by stabbing him in the eye on a London underground platform in 1992, three months after being discharged from hospital with no adequate supervision.
The report says that in almost every case professional staff felt the offence was unpredictable so there was nothing that could have been done to prevent the death.
But the researchers concluded: 'There was clear evidence that in almost 60 per cent of cases the homicides followed a spell where the patient had failed to co-operate in the treatment plan proposed for them. In an appreciable number of cases, 13 out of the 22, there had been some fall off in attendance for treatment or some failure to take prescribed medication.'
The report concludes: 'There is thus raised, but not answered, the question of whether a level of supervision beyond what was provided, might have served to control the mental state in the homicidal patient.
'Modification to the questionnaire from the Inquiry may encourage respondents to consider more innovative or imaginative ways of offering close supervision of this difficult group of patients.'
The monitoring of homicides by psychiatric patients is continuing and the inquiry, chaired by Professor Andrew Sims, a former president of the RCP, is also examining cases of suicides by mental patients.
Jayne Zito, who was widowed after just three months of marriage when her husband was killed, has formed a trust to campaign for a national support network for seriously mentally ill people.
A spokeswoman for the Zito Trust said: 'The figures released by the confidential inquiry show the shocking cases of how inadequate care for seriously mentally ill people in the community can fail them, their families and victims of violence. The Government must listen to the findings of the inquiry and give some meat to its promises of stopping people falling through the net - this means funding, help, support and care.'
Tomorrow, the National Schizophrenia Fellowship publishes an analysis of pounds 500m worth of services it estimates are needed to provide full community care. Eve Thompson, the chairwoman, said: 'These tragedies are only the tip of the iceberg . . . If premature discharges and grossly underfunded community services persist then tragedies will continue'.
John Bowis, parliamentary secretary at the Department of Health, welcomed the report and said the Government had already responded to public concern with a 10-point plan including supervision registers, new guidance on the discharge of mentally disordered people and better training of key workers who would be responsible for discharged patients.